An information processing device is known which is capable of executing a power saving function (called “EEE (abbreviation of Energy Efficient Ethernet) function” below) according to IEEE (abbreviation of The Institute of Electrical and Electronics Engineers. Inc.) 802.3az. The information processing device executes an auto-negotiation with an external device connected thereto via a LAN cable, and determines whether a communication according to the EEE function can be executed with the external device. The information processing device informs a user of the result of the determination. In a case where the EEE function is used after an establishment of a communication link between the information processing device and the external device, the communication link can be maintained with less power consumption than in a case where the EEE function is not used.